WEST POINT -- Davis County Attorney Troy Rawlings says he isn't prepared to file charges against a 15-year-old boy suspected of fatally stabbing his two younger brothers Wednesday.
Rawlings said he is trying to find out more about the boy and killings that stunned the community.
Aza Vidinhar is in custody after authorities investigating the stabbing deaths of his younger adopted brothers found him miles away with traces of blood on him, officials say.
He was arrested Thursday in the deaths of the boys, ages 4 and 10, at the family home in a subdivision of new houses and tidy lawns, police said.
"He spoke bluntly with our investigators," said Davis County Sheriff Todd Richardson.
Officials described Vidinhar as an honor student and a long-distance runner on the track team -- when his mother wasn't home-schooling him, while neighbors said he was socially awkward with a speech impediment.
"I'm still in shock," neighbor Karin Jackson said Thursday. "This is a wonderful neighborhood and the kids are usually outside playing."
The younger brothers died from knife wounds following the attack, according to a preliminary report by the medical examiner.
Vidinhar allegedly acted alone, apparently on an impulse, Richardson said.
At first, Vidinhar was thought to be a third victim, missing from the crime scene, and police publicized his name while looking for him.
"There are more questions than answers at this point," Rawlings said. "This teen in custody has a presumption of innocence. Facts are being gathered to assist with critical decisions."
Vidinhar and his two younger brothers had been left home alone. The family has six children, and police said their mother took the other children to a dance recital, returning to find the body of the 4-year-old. She called police, who found the body of the 10-year-old in the basement.
Their father, reportedly a Department of Defense engineer, was away in Alabama.
Four of the family's six children are adopted, and neighbors spoke highly of them.
But Vidinhar was "different," said Scott Green, an ex-neighbor who said he once found the boy throwing dozens of rocks over a fence onto his trampoline.
The father is an engineer working for the Air Force, Green said. At first, authorities said he was active duty military, but later said they weren't certain about his status with what they believed was the Air Force. The couple had spent time in South Korea before moving to Utah, Green said.
The 10-year-old adopted boy spent a lot of time at his house, playing with Green's daughter -- "best of pals," he said.
Vidinhar was enrolled as a ninth-grader at West Point Junior High and was a member of the National Honors Society and a distance runner on the track team, said Davis School District spokesman Chris Williams.
Williams said the youths' parents moved them in and out of public school over the years, sometimes home-schooling them.
Neighbors who were interviewed were unanimous: Vidinhar kept to himself and wasn't seen except when jogging.
"We never had a history file on him, except for the time he did a runaway," Richardson said.
It was two or three years ago, police and neighbors said. After a seven-hour search, police found him four miles away at a Wendy's restaurant.
The sheriff said Vidinhar had undisclosed, minor injuries when found late Wednesday walking along a street in nearby Layton. The injuries were consistent with having been involved in an attack, Richardson said. He declined to elaborate.
"It's very sad," said Lindsey Caballero, a mother who lives across the street from the suspect's home. "It's scary. It goes to show you never know what's happening."
Standard-Examiner staff contributed to this article.